High modulus glass fibre composition, and glass fibre and composite material thereof

ABSTRACT

A high-modulus glass fiber composition, and a glass fiber and a composite material therefrom. The glass fiber composition comprises the following components in weight percentage: SiO2 55.7 to 58.9%, Al2O3 15 to 19.9%, Y2O3 0.1 to 4.3%, La2O3 less than or equal to 1.5%, CeO2 less than or equal to 1.2%, CaO 6 to 10%, MgO 9.05 to 9.95%, SrO less than or equal to 2%, Li2O+Na2O+K2O less than or equal to 0.99%, Li2O less than or equal to 0.65%, Fe2O3 less than 1%, TiO2 0.1 to 1.5%; wherein, the range of the weight percentage ratio C1=Y2O3/(Y2O3+La2O3+CeO2) is greater than 0.6. The composition can greatly improve the elastic modulus of glass, significantly reduce liquidus temperature and forming temperature of the glass, greatly reduce the crystallization rate of molten glass and bubble amount under the same conditions, and therefore is more suitable for large-scale tank furnace production of high-modulus fiberglass with low bubble amount.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is the U.S. national phase of PCT ApplicationNo. PCT/CN2016/086022 filed on Jun. 16, 2016, which claims priority toChinese Patent Application NO. 201610403705.7 filed on Jun. 7, 2016 andentitled “HIGH MODULUS GLASS FIBRE COMPOSITION, AND GLASS FIBRE ANDCOMPOSITE MATERIAL THEREOF”, the disclosures of which is areincorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The invention relates to high-modulus glass fiber compositions, inparticular, to high-modulus glass fiber compositions that can be used asa reinforcing base material for advanced composites, and to the glassfiber and composite material therefrom.

BACKGROUND OF THE INVENTION

Glass fiber is an inorganic fiber material that can be used to reinforceresins to produce composite materials with good performance. As areinforcing base material for advanced composite materials, high-modulusglass fibers were originally used mainly in the national defenseindustry, such as aeronautic, aerospace and military industry. With theprogress of science and technology and the development of economy,high-modulus glass fibers have been widely used in civil and industrialfields such as wind blades, pressure vessels, offshore oil pipes, andauto industry.

The original high-modulus glass compositions were based on anMgO—Al₂O₃—SiO₂ system, and a typical composition was the S-2 glassdeveloped by OC company of US. Its modulus is 89-90 GPa; however, theproduction of S-2 glass is excessively difficult, as its formingtemperature is up to about 1571° C. and its liquidus temperature is upto 1470° C. and therefore, it is difficult to realize large-scaleindustrial production. Then OC company gave up the production of S-2glass fiber and assigned the patent to AGY company of US.

Thereafter, OC company has developed HiPer-tex glass. Its modulus is87-89 GPa, which was a trade-off for production scale by sacrificingsome of the glass properties. However, since these designed solutionsjust made a simple improvement on the S-2 glass, the forming temperatureand liquidus temperature of the glass fiber were still high and theproduction of glass remained highly difficult, it is also difficult torealize large-scale tank furnace production. Then OC company gave up theproduction of HiPer-tex glass fiber and assigned the patent of HiPer-texglass fiber to 3B company of Europe.

Saint-Gobain of France has developed R glass that is based on anMgO—CaO—Al₂O₃—SiO₂ system, and its modulus is 86-89 GPa. However, thetotal content of SiO₂ and Al₂O₃ remains high in the traditional R glass,and there is no effective solution to improve the crystallizationperformance, as the ratio of Ca to Mg is inappropriately designed, thuscausing difficulty in fiber formation as well as a great risk ofcrystallization, high surface tension and fining difficulty of moltenglass. The forming temperature is up to about 1410° C. and the liquidustemperature is up to 1350° C. All these have caused difficulty inattenuating glass fiber and consequently resulting in realizinglarge-scale tank furnace production.

Nanjing Fiberglass Research & Design Institute Co. Ltd in China hasdeveloped an HS2 glass having a modulus of 84-87 GPa. The HS2 glassmainly comprises SiO₂, Al₂O₃ and MgO, and certain amounts of Li₂O, B₂O₃,CeO₂ and Fe₂O₃ are also introduced; its forming temperature is onlyabout 1245° C. and its liquidus temperature is 1320° C. Bothtemperatures are much lower than those of S glass fiber. However, sinceits forming temperature is lower than its liquidus temperature thusresulting in a negative ΔT value, which is unfavorable for the controlof glass fiber attenuation, the forming temperature has to be increasedand specially-shaped tips of bushing have to be used to prevent a glasscrystallization phenomenon from occurring in the fiber drawing process.This causes difficulty in temperature control and also makes itdifficult to realize large-scale tank furnace production.

In summary, we have found that, various kinds of high-modulus glassfibers at this stage generally face production difficulty in large-scaletank furnace production, such as high liquidus temperature, highcrystallization rate, high forming temperature, high surface tension andfining difficulty of molten glass, and a narrow temperature range (ΔT)for fiber formation and even a negative ΔT. For this reasons, mostcompanies tend to reduce the production difficulty by sacrificing someof the glass properties. Thus, the modulus of the above-mentioned glassfibers cannot be improved with the growth of production scale, and themodulus bottleneck has long remained unresolved in the production of theS glass fiber.

SUMMARY OF THE INVENTION

The present invention aims to provide a high-modulus glass fibercomposition that can solve the aforesaid problems. The composition cannot only significantly improve glass modulus, but also solve theproduction problems of traditional high-modulus glasses, such as highcrystallization risk, fining difficulty and the difficulty of realizingefficient large-scale tank furnace production. The composition cansignificantly reduce the liquidus temperature, crystallization rate ofmolten glass and the bubble amount under the same conditions, andtherefore is more suitable for large-scale tank furnace production ofhigh-modulus fiberglass with a low bubble amount.

According to one aspect of the present invention, a glass fibercomposition is provided comprising the following components expressed asweight percentage:

SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% CaO  6-10% MgO 9.05-9.95% SrOless than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99%Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6.

Wherein, the total content of La₂O₃ and CeO₂ is further restricted to be0.1-2% by weight percentage.

Wherein, the range of the weight percentage ratio C2=SiO₂/CaO is furtherrestricted to be 5.8-9.3.

Wherein, the range of the weight percentage ratio C3=MgO/(CaO+SrO) isfurther restricted to be 0.9-1.6.

Wherein, the content of Li₂O is further restricted to be 0.05-0.55% byweight percentage.

Wherein, the content of Y₂O₃ is further restricted to be 0.5-3.9% byweight percentage.

Wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is further restricted to be 0.75-0.97.

Wherein, the glass fiber composition comprises the following componentsexpressed as weight percentage:

SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% CaO  6-10% MgO 9.05-9.95% SrOless than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99%Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

Wherein, the content of La₂O₃ is further restricted to be 0.05-1.2% byweight percentage.

Wherein, the content of CeO₂ is further restricted to be 0.05-1% byweight percentage.

Wherein, the glass fiber composition comprises the following componentsexpressed as weight percentage:

SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.1-4.3% La₂O₃ 0.05-1.2%  CeO₂0.05-1%   La₂O₃ + CeO₂ 0.1-2%   CaO  6-10% MgO 9.05-9.95% SrO less thanor equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O lessthan or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

Wherein, the glass fiber composition comprises the following componentsexpressed as weight percentage:

SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.5-3.9% La₂O₃ 0.05-1.2%  CeO₂0.05-1%   La₂O₃ + CeO₂ 0.1-2%   CaO  6-10% MgO 9.05-9.95% SrO less thanor equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O lessthan or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1%  

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

Wherein, the glass fiber composition comprises the following componentsexpressed as weight percentage:

SiO₂ 56.5-58.9% Al₂O₃   16-19.5% Y₂O₃ 0.5-3.9% La₂O₃ 0.05-1.2%  CeO₂0.05-1%   La₂O₃ + CeO₂ 0.1-2%   CaO 6.8-9.3% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O0.05-0.55% Fe₂O₃ less than 1% TiO₂ 0.1-1%  

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.75-0.97, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

Wherein, the content of CaO is further restricted to be 8-9.3% by weightpercentage.

Wherein, the total content of Li₂O+Na₂O+K₂O is further restricted to be0.4-0.94% by weight percentage.

Wherein, the total content of Na₂O+K₂O is further restricted to be0.15-0.55% by weight percentage.

Wherein, the range of the weight percentage ratio C2=SiO₂/CaO is furtherrestricted to be 6.7-8.

Wherein, the range of the weight percentage ratio C3=MgO/(CaO+SrO) isfurther restricted to be 1.05-1.4.

Wherein, the range of the weight percentage ratio C4=La₂O₃/CeO₂ isfurther restricted to be greater than 1.

Wherein, the content of Y₂O₃ is further restricted to be 1.3-3.9% byweight percentage.

Wherein, the total content of Y₂O₃+La₂O₃+CeO₂ is further restricted tobe 1.4-4.2% by weight percentage.

Wherein, the glass fiber composition can further comprise B₂O₃ with acontent range of 0-3% by weight percentage.

According to another aspect of this invention, a glass fiber producedwith said glass fiber composition is provided.

According to yet another aspect of this invention, a composite materialincorporating said glass fiber is provided.

According to the high-modulus glass fiber composition of this invention,the main innovation is that, the composition introduces the rare earthoxides Y₂O₃, La₂O₃ and CeO₂, makes full use of the mixed rare eartheffect between them, reasonably controls the ratios ofY₂O₃/(Y₂O₃+La₂O₃), La₂O₃/CeO₂, SiO₂/CaO and MgO/(CaO+SrO), reasonablydesigns the ranges of contents of Y₂O₃, La₂O₃, CeO₂, Li₂O, CaO, MgO,La₂O₃+CeO₂, Y₂O₃+La₂O₃+CeO₂, Na₂O+K₂O and Li₂O+Na₂O+K₂O, and makes fulluse of the mixed alkali earth effect of CaO, MgO and SrO and the mixedalkali effect of K₂O, Na₂O and Li₂O; furthermore, the compositionselectively introduces a small amount of B₂O₃.

Specifically, the high-modulus glass fiber composition according to thepresent invention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% CaO     6-10% MgO 9.05-9.95% SrOless than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99%Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6.

The effect and content of each component in said glass fiber compositionis described as follows:

SiO₂ is a main oxide forming the glass network and has the effect ofstabilizing all the components. In the glass fiber composition of thepresent invention, the restricted content range of SiO₂ is 55.7-58.9%expressed as weight percentage. Preferably, the SiO₂ content range canbe 56.5-58.9% expressed as weight percentage.

Al₂O₃ is another oxide forming the glass network. When combined withSiO₂, it can have a substantive effect on the mechanical properties ofthe glass. The restricted content range of Al₂O₃ in the glass fibercomposition of this invention is 15-19.9% expressed as weightpercentage. Al₂O₃ content being too low will make it impossible to havehigh mechanical properties; Al₂O₃ content being too high will cause theglass viscosity to be excessively high thereby resulting in melting andfining issues. Preferably, the range of Al₂O₃ content can be 16-19.5%expressed as weight percentage. More preferably, the range of Al₂O₃content can be 16.7-19.3% expressed as weight percentage.

Y₂O₃ is an important rare earth oxide. The inventors have found that ithas particular effects in improving elastic modulus and inhibitingcrystallization tendency of the glass. Y³⁺ ion is generally in the gapsof glass network as the network modifying ion, for Y³⁺ ion is difficultto enter into the glass structure. Y³⁺ ion has high coordination number,high field strength, high electric charge and strong accumulationability, and can grab free oxygen to compensate network defect, improvethe stability of glass structure and the elastic modulus of glass.Meanwhile, it also can effectively inhibit the movement and arrangementof other ions, thereby reducing crystallization tendency of glass.Additionally, the inventors have found that, increasing the content ofY₂O₃ does not lead to significant effect on the improvement ofmechanical properties when the content of Y₂O₃ exceeds 4.3%, and theglass density would be significantly increased, thus restricting theimprovement of specific modulus and specific strength; in this case, thespecific modulus and specific strength even could be reduced undercertain conditions, which is unfavorable for the lightweight of glassfiber.

La₂O₃ is also an important rare earth oxide. The inventors have foundthat, when used alone, La₂O₃ shows a weaker effect in increasing themodulus and inhibiting the crystallization, as compared with Y₂O₃.However, the synergistic effect of combination of rare earth oxides isremarkable when these two rare earth oxides are simultaneously used in areasonably controlled ratio there between, and the effect on increasingthe glass modulus and inhibiting the glass crystallization isunexpectedly superior to that of the separate use of Y₂O₃ or La₂O₃. Inthe inventors' view, Y₂O₃ and La₂O₃ are of the same group of oxides andtheir physical and chemical properties are similar except for havingdifferent coordination states. Generally, the yttrium ion is featuredwith six-coordination while the lanthanum ion with eight-coordination.Therefore, the combination of the two oxides with a reasonably designedratio would have the following beneficial effects. First, it can offermore coordination structure of network modifying ions, the mainstructure being six-coordinated yttrium ion combined with the structureof eight-coordinate lanthanumd ion, which helps to improve the stabilityof glass structure and the elastic modulus of glass. Second, lanthanumoxide can increase the amount of free oxygen and promote moretransitions from [AlO₆] to [AlO₄], thus further enhancing the integrityof glass structure and increasing the glass modulus. Third, sincevarious ions are restricting each other, the probability of regulararrangement of ions will also be reduced when the temperature islowered, thus helping to significantly reduce the growth rate ofcrystals and further improve the crystallization resistance of glass.However, as the molar mass and ionic radiuses of lanthanum arerelatively large, and too many eight-coordinated ions would affect thestability of structure, the added amount of lanthanum should not be toohigh.

CeO₂ is an important rare earth glass fining agent. The inventors havefound that, replacing part of Y₂O₃ or La₂O₃ with a small amount of CeO₂can have a significant effect in increasing the glass modulus andinhibiting the glass crystallization, and the effect will be morepronounced when the three rare earth oxides, i.e., Y₂O₃, La₂O₃ and CeO₂,are used simultaneously with reasonably designed ratios there between.In the inventors' view, on the one hand, CeO₂ can provide more freeoxygen to yttrium for compensating network defect; on the other hand,the three rare earth ions with different ionic radiuses and fieldstrengths can enhance the compact stacking effect of the structure,which not only further enhances the integrity of glass structure andimproves glass properties, but also strengthens the restraining forcebetween the ions to improve the crystallization performance of theglass.

Therefore, in the glass fiber composition of the present invention, therestricted range of the content of Y₂O₃ is 0.1-4.3% expressed as weightpercentage. Preferably, the restricted range of the content of Y₂O₃ canbe 0.5-3.9% expressed as weight percentage. More preferably, therestricted range of the content of Y₂O₃ can be 1.3-3.9% expressed asweight percentage. The restricted range of the content of La₂O₃ is lessthan or equal to 1.5% expressed as weight percentage. Preferably, therestricted range of the content of La₂O₃ can be 0.05-1.2% expressed asweight percentage. The restricted range of the content of CeO₂ is lessthan or equal to 1.2% expressed as weight percentage. Preferably, therestricted range of the content of CeO₂ can be 0.05-1% expressed asweight percentage.

Meanwhile, the restricted range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6. Preferably, therestricted range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) can be greater than 0.7. More preferably, therestricted range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) can be 0.75-0.97. Meanwhile, the range of thetotal content of La₂O₃+CeO₂ can further be 0.1-2% expressed as weightpercentage. The range of the weight percentage ratio C4=La₂O₃/CeO₂ canfurther be greater than 1. The range of the total content ofY₂O₃+La₂O₃+CeO₂ can further be 1.4-4.2% expressed as weight percentage.

CaO, MgO and SrO mainly have the effect of controlling glasscrystallization, regulating glass viscosity, and controlling thehardening rate of molten glass. Unexpected effects especially on thecontrol of glass crystallization have been obtained by controlling thecontents of CaO, MgO and SrO and the ratios thereof. Generally, thecrystalline phase after the crystallization of high-performance glassesbased on an MgO—CaO—Al₂O₃—SiO₂ system mainly comprises diopside(CaMgSi₂O₆) and anorthite (CaAl₂Si₂O₈). In order to effectively inhibitthe crystallization tendency of the two crystalline phases, reduce theliquidus temperature and the crystallization rate of glass, byreasonably designing the ranges of contents of CaO, MgO and SrO and theratios thereof, making full use of the mixed alkali earth effect toachieve a compact stacking structure, more energy is needed for thecrystal nucleuses to form and grow, thereby inhibiting thecrystallization tendency of glass and effectively optimizing thehardening rate of molten glass. The inventors have found that, thecontent of MgO in the composition of this invention is greatly increasedcompared with the content of traditional R glass and improved R glass,and the composition can have higher elastic modulus, lowercrystallization temperature and rate when the range of the content ofMgO is rigidly kept at 9.05-9.95% expressed as weight percentage and therange of the weight percentage ratio of MgO/(CaO+SrO) is reasonablydesigned to be 0.9-1.6. The inventors have further found that, thegrowth of anorthite could be effectively controlled to inhibit thecrystallization tendency of glass by reasonably controlling the ratio ofSiO₂/CaO, as the growth momentum of diopside is relatively strong in thetwo crystals due to the relatively high content of MgO in thecomposition of this invention.

Therefore, in the glass fiber composition of the present invention, therestricted range of the content of MgO is 9.05-9.95% expressed as weightpercentage. The restricted range of the content of CaO is 6-10%expressed as weight percentage. Preferably, the range of the content ofCaO can be 6.8-9.3% expressed as weight percentage.

Additionally, in some technical solutions, the range of the content ofCaO can further be 8-9.3% expressed as weight percentage. The range ofthe content of SrO can further be less than or equal to 2% expressed asweight percentage.

Meanwhile, the range of the weight percentage ratio C2=SiO₂/CaO canfurther be 5.8-9.3. Preferably, the range of the weight percentage ratioC2=SiO₂/CaO can be 6.3-8.5. More preferably, the range of the weightpercentage ratio C2=SiO₂/CaO can be 6.7-8. The range of the weightpercentage ratio C3=MgO/(CaO+SrO) can further be 0.9-1.6. Preferably,the range of the weight percentage ratio C3=MgO/(CaO+SrO) can be 1-1.5.More preferably, the range of the weight percentage ratioC3=MgO/(CaO+SrO) can be 1.05-1.4.

Both K₂O and Na₂O are good fluxing agents that can reduce glassviscosity. The inventors have found that, replacing Na₂O with K₂O whilekeeping the total amount of alkali metal oxides unchanged can reduce thecrystallization tendency of glass and improve the fiberizingperformance. Li₂O can not only reduce the glass viscosity dramaticallyto improve the melting performance, but also noticeably help to improvemechanical properties, compared with Na₂O and K₂O. In addition, a smallamount of Li₂O can provide considerable free oxygen, thereby promotingmore aluminum ions to form tetrahedral coordination that would helpstrengthen the glass network and further reduce crystallization tendencyof glass. But the added amount of alkali metal ions should not be toohigh, as the high content of alkali metal ions will reduce the corrosionresistance of glass. Additionally, the rare earth oxides have relativelystrong alkalinity, and can play a similar role as the alkali metaloxides and the alkaline earth metal oxides in some respects. Therefore,in the glass fiber composition of the present invention, the range ofthe total content of Li₂O+Na₂O+K₂O is less than or equal to 0.99%expressed as weight percentage. The range of the content of Li₂O is lessthan or equal to 0.65% expressed as weight percentage. The range of thetotal content of Li₂O+Na₂O+K₂O can further be 0.4-0.94% expressed asweight percentage. The range of the content of Li₂O can further be0.05-0.55% expressed as weight percentage. The range of the totalcontent of Na₂O+K₂O can further be 0.15-0.55% expressed as weightpercentage.

The introduction of Fe₂O₃ facilitates the melting of glass and can alsoimprove the crystallization properties of glass. However, since ferricions and ferrous ions have coloring effects, the introduced amountshould be limited. Therefore, in the glass fiber composition of thepresent invention, the restricted range of the content of Fe₂O₃ is lessthan 1% expressed as weight percentage.

TiO₂ can not only reduce the glass viscosity at high temperature, butalso has a certain fluxing effect. However, since titanium ions havecoloring effects, in the glass fiber composition of this invention, therestricted range of the content of TiO₂ is 0.1-1.5% expressed as weightpercentage. Preferably, the range of TiO₂ content can be 0.1-1%expressed as weight percentage.

In the glass fiber composition of this invention, a small amount of B₂O₃can be selectively introduced, which can further improve thecrystallization performance of glass. Therefore, in the glass fibercomposition of the present invention, the restricted range of thecontent of B₂O₃ can be 0-3% expressed as weight percentage.

In addition to aforementioned components, small amount of othercomponents may be present in the glass composition according to thepresent invention, and the total weight percentage of the othercomponents is less than or equal to 2%.

In the glass fiber composition of the present invention, the beneficialeffects produced by the aforementioned selected ranges of the componentswill be explained through the specific experimental data provided below.

The following are embodiments of preferred content ranges of thecomponents contained in the glass fiber composition according to thepresent invention.

PREFERRED EMBODIMENT 1

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% CaO     6-10% MgO 9.05-9.95% SrOless than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99%Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, and the range of theweight percentage ratio C2=SiO₂/CaO is 5.8-9.3.

PREFERRED EMBODIMENT 2

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% CaO     6-10% MgO 9.05-9.95% SrOless than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99%Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.75-0.97.

PREFERRED EMBODIMENT 3

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% CaO     6-10% MgO 9.05-9.95% SrOless than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99%Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

PREFERRED EMBODIMENT 4

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃  0.05-1.2% CeO₂less than or equal to 1.2% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂O less than orequal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

PREFERRED EMBODIMENT 5

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂Oless than or equal to 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

PREFERRED EMBODIMENT 6

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.5-3.9% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂Oless than or equal to 0.65% Fe₂O₃ less than 1% TiO₂    0.1-1%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

PREFERRED EMBODIMENT 7

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 56.5-58.9% Al₂O₃  16-19.5% Y₂O₃  0.5-3.9% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO  6.8-9.3% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O0.05-0.55% Fe₂O₃ less than 1% TiO₂    0.1-1%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.75-0.97, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

PREFERRED EMBODIMENT 8

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO    8-9.3% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂Oless than or equal to 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

PREFERRED EMBODIMENT 9

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O  0.4-0.94% Li₂O less than or equalto 0.65% Fe₂O₃ less than 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weightpercentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.

PREFERRED EMBODIMENT 10

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.5-3.9% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂Oless than or equal to 0.65% Fe₂O₃ less than 1% TiO₂    0.1-1%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.7-8, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

PREFERRED EMBODIMENT 11

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.5-3.9% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂Oless than or equal to 0.65% Fe₂O₃ less than 1% TiO₂    0.1-1%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1.05-1.4.

PREFERRED EMBODIMENT 12

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.1-4.3% La₂O₃ less than or equalto 1.5% CeO₂ less than or equal to 1.2% La₂O₃ + CeO₂    0.1-2% CaO    6-10% MgO 9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂Oless than or equal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ lessthan 1% TiO₂  0.1-1.5%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, and the range of theweight percentage ratio C4=La₂O₃/CeO₂ is greater than 1.

PREFERRED EMBODIMENT 13

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  1.3-3.9% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% CaO     6-10% MgO 9.05-9.95% SrO lessthan or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂Oless than or equal to 0.65% Fe₂O₃ less than 1% TiO₂    0.1-1%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

PREFERRED EMBODIMENT 14

The high-modulus glass fiber composition according to the presentinvention comprises the following components expressed as weightpercentage:

SiO₂ 55.7-58.9% Al₂O₃  15-19.9% Y₂O₃  0.5-3.9% La₂O₃  0.05-1.2% CeO₂  0.05-1% La₂O₃ + CeO₂    0.1-2% Y₂O₃ + La₂O₃ + CeO₂  1.4-4.2% CaO    6-10% MgO 9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂Oless than or equal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ lessthan 1% TiO₂    0.1-1%

wherein, the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weightpercentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weightpercentage ratio C3=MgO/(CaO+SrO) is 1-1.5.

DETAILED DESCRIPTION OF THE INVENTION

In order to better clarify the purposes, technical solutions andadvantages of the examples of the present invention, the technicalsolutions in the examples of the present invention are clearly andcompletely described below. Obviously, the examples described herein arejust part of the examples of the present invention and are not all theexamples. All other exemplary embodiments obtained by one skilled in theart on the basis of the examples in the present invention withoutperforming creative work shall all fall into the scope of protection ofthe present invention. What needs to be made clear is that, as long asthere is no conflict, the examples and the features of examples in thepresent application can be arbitrarily combined with each other.

The basic concept of the present invention is that, the glass fibercomposition comprises the following components expressed as percentageby weight: SiO₂ 55.7-58.9%, Al₂O₃ 15-19.9%, Y₂O₃ 0.1-4.3%, La₂O₃ lessthan or equal to 1.5%, CeO₂ less than or equal to 1.2%, CaO 6-10%, MgO9.05-9.95%, SrO less than or equal to 2%, Li₂O+Na₂O+K₂O less than orequal to 0.99%, Li₂O less than or equal to 0.65%, Fe₂O₃ less than 1% andTiO₂ 0.1-1.5%, and the range of the weight percentage ratioC1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6. The composition can notonly significantly improve glass modulus, but also solve the productionproblems of traditional high-modulus glass, such as high crystallizationrisk, fining difficulty and the difficulty of realizing efficientlarge-scale tank furnace production. The composition can significantlyreduce liquidus temperature, crystallization rate of molten glass andbubble amount under the same conditions, and therefore is more suitablefor large-scale tank furnace production of high-modulus fiberglass withlow bubble amount.

The specific content values of SiO₂, Al₂O₃, Y₂O₃, La₂O₃, CeO₂, CaO, MgO,Li₂O, Na₂O, K₂O, Fe₂O₃, TiO₂ and SrO in the glass fiber composition ofthe present invention are selected to be used in the examples, which arecompared with the properties of S glass, traditional R glass andimproved R glass in terms of the following six property parameters:

(1) Forming temperature, the temperature at which the glass melt has aviscosity of 10³ poise.

(2) Liquidus temperature, the temperature at which the crystal nucleusesbegin to form when the glass melt cools off, i.e., the upper limittemperature for glass crystallization.

(3) ΔT value, which is the temperature differential between the formingtemperature and the liquidus temperature and indicates the temperaturerange at which fiber drawing can be performed.

(4) Crystallization peak temperature, the temperature of the strongestcrystallization peak in the DTA (Differential Thermal Analysis) test.Generally, the higher the temperature is, the more energy that thecrystal nucleuses need to grow, and the smaller crystallization tendencyof glass is.

(5) Elastic modulus, the modulus in the longitudinal directionindicating the ability of glass to resist elastic deformation, which isto be measured according to ASTM2343.

(6) Amount of bubbles, to be determined approximately in a procedure setout as follows: Use specific moulds to compress the batch materials ineach example into samples of same dimension, which will then be placedon the sample platform of a heating microscope. Heat the glass samplesaccording to standard procedures up to the pre-set spatial temperature1500° C., and then the glass sample is cooled off to the ambienttemperature without heat preservation. Finally, each of the glasssamples is examined microscopically under a polarizing microscope todetermine the amount of bubbles in the samples. Wherein, the amount ofbubbles is identified according to a specific scope of image of themicroscope.

The aforementioned six parameters and the methods of measuring them arewell-known to one skilled in the art. Therefore, the aforementionedparameters can be effectively used to explain the properties of theglass fiber composition of the present invention.

The specific procedures for the experiments are as follows: Eachcomponent can be acquired from the appropriate raw materials; the rawmaterials are mixed in the appropriate proportions so that eachcomponent reaches the final expected weight percentage; the mixed batchis melted and clarified; then the molten glass is drawn out through thetips of the bushings, thereby forming the glass fiber; the glass fiberis attenuated onto the rotary collet of a winder to form cakes orpackages. Of course, conventional methods can be used to deeply processthese glass fibers to meet the expected requirements.

The exemplary embodiments of the glass fiber composition according tothe present invention are given below.

EXAMPLE 1

SiO₂ 58.2% Al₂O₃ 18.0% CaO  8.2% MgO  9.8% Y₂O₃  3.4% La₂O₃ 0.43% CeO₂ 0.1% Na₂O 0.13% K₂O 0.30% Li₂O 0.49% Fe₂O₃ 0.46% TiO₂ 0.49%

wherein, the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.86,the weight percentage ratio C2=SiO₂/CaO is 7.11, the weight percentageratio C3=MgO/(CaO+SrO) is 1.20, and the weight percentage ratioC4=La₂O₃/CeO₂ is 4.3.

In Example 1, the measured values of the six parameters arerespectively:

Forming temperature 1298° C. Liquidus temperature 1198° C. ΔT 100° C.Crystallization peak temperature 1037° C. Elastic modulus  97.4 GPaAmount of bubbles 3

EXAMPLE 2

SiO₂ 57.8% Al₂O₃ 19.1% CaO  7.8% MgO  9.5% Y₂O₃  3.5% La₂O₃ 0.25% CeO₂0.15% Na₂O 0.20% K₂O 0.23% Li₂O 0.51% Fe₂O₃ 0.46% TiO₂ 0.50%

wherein, the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.90,the weight percentage ratio C2=SiO₂/CaO is 7.41, the weight percentageratio C3=MgO/(CaO+SrO) is 1.22, and the weight percentage ratioC4=La₂O₃/CeO₂ is 1.67.

In Example 2, the measured values of the six parameters arerespectively:

Forming temperature 1299° C. Liquidus temperature 1198° C. ΔT 101° C.Crystallization peak temperature 1038° C. Elastic modulus 98.5 GPaAmount of bubbles 2

EXAMPLE 3

SiO₂ 58.5% Al₂O₃ 17.5% CaO  8.1% MgO  9.8% Y₂O₃  3.9% La₂O₃ 0.25% CeO₂0.05% Na₂O 0.11% K₂O 0.31% Li₂O 0.50% Fe₂O₃ 0.46% TiO₂ 0.52%

wherein, the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.93,the weight percentage ratio C2=SiO₂/CaO is 7.22, the weight percentageratio C3=MgO/(CaO+SrO) is 1.21, and the weight percentage ratioC4=La₂O₃/CeO₂ is 5.0.

In Example 3, the measured values of the six parameters arerespectively:

Forming temperature 1298° C. Liquidus temperature 1200° C. ΔT 98° C.Crystallization peak temperature 1039° C. Elastic modulus 99.4 GPaAmount of bubbles 3

EXAMPLE 4

SiO₂ 58.1% Al₂O₃ 18.3% CaO  8.1% MgO  9.8% Y₂O₃  3.2% La₂O₃  0.3% CeO₂ 0.1% Na₂O 0.14% K₂O 0.35% Li₂O 0.43% Fe₂O₃ 0.46% TiO₂ 0.72%

wherein, the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.89,the weight percentage ratio C2=SiO₂/CaO is 7.17, the weight percentageratio C3=MgO/(CaO+SrO) is 1.21, and the weight percentage ratioC4=La₂O₃/CeO₂ is 3.0.

In Example 4, the measured values of the six parameters arerespectively:

Forming temperature 1298° C. Liquidus temperature 1201° C. ΔT 97° C.Crystallization peak temperature 1035° C. Elastic modulus 96.8 GPaAmount of bubbles 3

EXAMPLE 5

SiO₂ 58.5% Al₂O₃ 17.4% CaO 8.05% MgO  9.8% Y₂O₃  3.6% La₂O₃ 0.07% CeO₂0.05% Na₂O 0.11% K₂O 0.31% Li₂O 0.51% Fe₂O₃ 0.44% TiO₂ 0.46% SrO  0.6%

wherein, the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.97,the weight percentage ratio C2=SiO₂/CaO is 7.27, the weight percentageratio C3=MgO/(CaO+SrO) is 1.22, and the weight percentage ratioC4=La₂O₃/CeO₂ is 1.4.

In Example 5, the measured values of the six parameters arerespectively:

Forming temperature 1298° C. Liquidus temperature 1202° C. ΔT  96° C.Crystallization peak temperature 1035° C. Elastic modulus 98.1 Amount ofbubbles 4

Comparisons of the property parameters of the aforementioned examplesand other examples of the glass fiber composition of the presentinvention with those of the S glass, traditional R glass and improved Rglass are further made below by way of tables, wherein the componentcontents of the glass fiber composition are expressed as weightpercentage. What needs to be made clear is that the total amount of thecomponents in the examples is slightly less than 100%, and it should beunderstood that the remaining amount is trace impurities or a smallamount of components which cannot be analyzed.

TABLE 1A A1 A2 A3 A4 A5 A6 A7 Component SiO₂ 58.4 58.5 58.1 58.1 58.158.6 58.3 Al₂O₃ 19.3 17.4 18.3 17.7 18.3 19.6 17.9 CaO 8.1 8.05 6.8 8.18.1 8.7 8.3 MgO 9.95 9.8 9.8 9.8 9.8 9.9 9.9 Y₂O₃ 0.25 3.6 3.2 3.2 3.20.5 2.6 La₂O₃ 0.1 0.07 0.3 — 0.3 0.2 1.2 CeO₂ 0.05 0.05 0.1 1.0 0.1 0.05— Na₂O 0.14 0.11 0.14 0.14 0.14 0.15 0.13 K₂O 0.19 0.31 0.35 0.35 0.350.19 0.26 Li₂O 0.64 0.51 0.43 0.43 0.43 0.65 0.51 Fe₂O₃ 0.53 0.44 0.460.46 0.46 0.46 0.44 TiO₂ 1.35 0.46 0.72 0.72 0.72 1.0 0.46 SrO 1.0 0.61.3 — — — — Ratio C1 0.63 0.97 0.89 0.76 0.89 0.67 0.68 C2 7.21 7.278.54 7.17 7.17 6.74 7.02 C3 1.23 1.22 1.44 1.21 1.21 1.14 1.18 C4 2.01.4 3.0 — 3.0 4.0 — Parameter Forming 1300 1298 1303 1297 1298 1305 1298temperature/° C. Liquidus 1208 1202 1203 1205 1201 1208 1205temperature/° C. ΔT/° C. 92 96 100 92 97 97 93 Crystallization 1032 10351036 1032 1035 1032 1031 peak temperature/° C. Elastic 93.8 98.1 97.496.1 96.8 94.2 95.6 modulus/GPa Amount of 6 4 5 2 4 5 5 bubbles/pcs

TABLE 1B A8 A9 A10 A11 A12 A13 A14 Component SiO₂ 58.6 57.8 57.8 57.857.7 58.9 58.1 Al₂O₃ 18.1 19.1 19.1 19.1 19.05 15.9 19.5 CaO 7.5 7.8 7.87.8 8.6 9.3 8.3 MgO 9.4 9.5 9.5 9.5 9.05 9.95 9.95 Y₂O₃ 4.3 3.5 3.5 3.53.2 3.5 1.5 La₂O₃ 0.15 0.25 0.4 — 0.4 0.35 0.55 CeO₂ 0.05 0.15 — — 0.10.15 0.15 Na₂O 0.14 0.20 0.20 0.20 0.20 0.17 0.13 K₂O 0.40 0.23 0.230.23 0.23 0.26 0.21 Li₂O 0.25 0.51 0.51 0.51 0.51 0.49 0.61 Fe₂O₃ 0.510.46 0.46 0.46 0.46 0.39 0.44 TiO₂ 0.60 0.50 0.50 0.90 0.50 0.64 0.56SrO — — — — — — — Ratio C1 0.96 0.90 0.90 1.0 0.86 0.90 0.68 C2 7.817.41 7.41 7.41 6.71 6.33 7.0 C3 1.25 1.22 1.22 1.22 1.05 1.07 1.20 C43.0 1.67 — — 4.0 2.33 3.67 Parameter Forming 1298 1299 1298 1300 12991296 1304 temperature/° C. Liquidus 1200 1198 1204 1210 1203 1206 1203temperature/° C. ΔT/° C. 98 101 94 90 96 90 101 Crystallization 10401038 1033 1024 1035 1033 1032 peak temperature/° C. Elastic 98.4 98.597.0 96.0 96.6 96.0 94.6 modulus/GPa Amount of 3 2 5 8 4 3 4 bubbles/pcs

TABLE 1C Traditional Improved A15 A16 A17 A18 S glass R glass R glassComponent SiO₂ 58.1 57.8 58.5 58.2 65 60 60.75 Al₂O₃ 19.05 19.3 17.518.0 25 25 15.8 CaO 7.85 7.6 8.1 8.2 — 9 13.9 MgO 9.95 9.7 9.8 9.8 10 67.9 Y₂O₃ 2.5 3.4 3.9 3.4 — — — La₂O₃ 0.4 0.2 0.25 0.43 — — — CeO₂ 0.20.1 0.05 0.1 — — — Na₂O 0.23 0.21 0.11 0.13 trace trace 0.73 amountamount K₂O 0.33 0.46 0.31 0.30 trace trace amount amount Li₂O 0.34 0.190.50 0.49 — — 0.48 Fe₂O₃ 0.46 0.46 0.46 0.46 trace trace 0.18 amountamount TiO₂ 0.59 0.58 0.52 0.49 trace trace 0.12 amount amount SrO — — —— — — — Ratio C1 0.81 0.92 0.93 0.86 — — — C2 7.40 7.61 7.22 7.11 — 6.674.37 C3 1.27 1.28 1.21 1.20 — 0.67 0.57 C4 2.0 2.0 5.0 4.3 — — —Parameter Forming 1301 1305 1298 1298 1571 1430 1278 temperature/° C.Liquidus 1203 1203 1200 1198 1470 1350 1210 temperature/° C. ΔT/° C. 98102 98 100 101 80 68 Crystallization 1035 1036 1039 1037 — 1010 1016peak temperature/° C. Elastic 95.5 96.9 99.4 97.4 89 88 87 modulus/GPaAmount of 4 4 3 3 40 30 25 bubbles/pcs

It can be seen from the values in the above tables that, compared withthe S glass and traditional R glass, the glass fiber composition of thepresent invention has the following advantages: (1) Much higher elasticmodulus. (2) Much lower liquidus temperature, which helps to reducecrystallization risk and increase the fiber drawing efficiency; muchhigher crystallization peak temperature, which means more energy isneeded for the crystal nucleuses to form and grow during thecrystallization process, that is to say, the crystallization rate of themolten glass of the present invention is lower under the same condition.(3) Much lower amount of bubbles, which means the fining performance ofthe molten glass of the present invention is excellent.

The S glass and traditional R glass cannot enable tank furnaceproduction. In order to reduce the difficulty of tank furnaceproduction, the improved traditional R glass sacrifices some of theglass properties to lower the liquidus temperature and formingtemperature. By contrast, the glass fiber composition of the presentinvention can not only provide sufficiently low liquidus temperature andless crystallization rate, but also be suitable for tank furnaceproduction, greatly improve the elasticity modulus of glass, and resolvethe bottleneck that the modulus of S glass and R glass cannot beimproved with the growth of the production scale.

Thus, the glass fiber composition of the present invention makes abreakthrough in elasticity modulus, crystallization properties andfining performance of the glass, as compared with the mainstreamhigh-modulus glasses, and greatly improves the elastic modulus, reducesthe crystallization risk of molten glass and bubble amount under thesame conditions, and therefore is more suitable for large-scale tankfurnace production of high-modulus fiberglass with low bubble amount.

Additionally, the glass fiber composition comprising three kinds of rareearth oxides, as compared with the glass fiber composition comprisingyttrium oxide as the only rare earth oxide (see Example A11), has thefollowing exceptional advantages: (a) Much higher crystallization peaktemperature, which means more energy is needed for the crystal nucleusesto form and grow during the crystallization process, that is to say, thecomposition has lower crystallization rate under the same condition; andhas lower liquidus temperature, which helps to reduce crystallizationrisk and increase the fiber drawing efficiency. (b) Much higher elasticmodulus. (c) Much lower amount of bubbles, which means the finingperformance of the molten glass of the present invention is excellent.For example, the crystallization peak temperature of Example A9 wasincreased by 14° C., the liquidus temperature was decreased by 12° C.,the elastic modulus was increased by 2.5 GPa and the amount of bubbleswas reduced by 75%, as compared with those respectively in A11. Thecomposition has remarkable improvement of various properties and offersunexpected technical effects.

The glass fiber composition according to the present invention can beused for making glass fibers having the aforementioned excellentproperties.

The glass fiber composition according to the present invention can beused in combination with one or more organic and/or inorganic materialsfor preparing composite materials having excellent performances, such asglass fiber reinforced base materials.

Finally, what should be made clear is that, in this text, the terms“contain”, “comprise” or any other variants are intended to mean“nonexclusively include” so that any process, method, article orequipment that contains a series of factors shall include not only suchfactors, but also include other factors that are not explicitly listed,or also include intrinsic factors of such process, method, object orequipment. Without more limitations, factors defined by the phrase“contain a . . . ” or its variants do not rule out that there are othersame factors in the process, method, article or equipment which includesaid factors.

The above examples are provided only for the purpose of illustratinginstead of limiting the technical solutions of the present invention.Although the present invention is described in details by way ofaforementioned examples, one skilled in the art shall understand thatmodifications can also be made to the technical solutions embodied byall the aforementioned examples or equivalent replacement can be made tosome of the technical features. However, such modifications orreplacements will not cause the resulting technical solutions tosubstantially deviate from the spirits and ranges of the technicalsolutions respectively embodied by all the examples of the presentinvention.

INDUSTRIAL APPLICABILITY OF THE INVENTION

The glass fiber composition of the present invention can not only havefavorable liquidus temperature and less crystallization rate, but alsobe suitable for tank furnace production, greatly improve the elasticitymodulus of glass, and resolve the bottleneck that the modulus of S glassand R glass cannot be improved with the growth of the production scale.The glass fiber composition of the present invention makes abreakthrough in elasticity modulus, crystallization properties andfining performance of the glass compared with the mainstreamhigh-modulus glass, greatly improves the elastic modulus, reduces thecrystallization risk of molten glass and bubble amount under the sameconditions, and therefore is more suitable for large-scale tank furnaceproduction of high-modulus fiberglass with low bubble amount.

The invention claimed is:
 1. A high-modulus glass fiber composition comprising the following components expressed as weight percentage: SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.1-4.3% La₂O₃ less than or equal to 1.5% CeO₂ less than or equal to 1.2% CaO  6-10% MgO 9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of total content of La₂O₃+CeO₂ expressed as weight percentage is 0.1-2%, the range of weight percentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of weight percentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.
 2. The high-modulus glass fiber composition of claim 1, wherein the content of Li₂O expressed as weight percentage is 0.05-0.55%.
 3. The high-modulus glass fiber composition of claim 1, wherein the content of Y₂O₃ expressed as weight percentage is 0.5-3.9%.
 4. The high-modulus glass fiber composition of claim 1, wherein the content of Y₂O₃ expressed as weight percentage is 1.3-3.9%.
 5. The high-modulus glass fiber composition of claim 1, wherein the content of La₂O₃ expressed as weight percentage is 0.05-1.2%.
 6. The high-modulus glass fiber composition of claim 1, wherein the content of CeO₂ expressed as weight percentage is 0.05-1%.
 7. The high-modulus glass fiber composition of claim 1, wherein the content of CaO expressed as weight percentage is 8-9.3%.
 8. The high-modulus glass fiber composition of claim 1, wherein the total content of Li₂O+Na₂O+K₂O expressed as weight percentage is 0.4-0.94%.
 9. The high-modulus glass fiber composition of claim 1, wherein the total content of Y₂O₃+La₂O₃+CeO₂ expressed as weight percentage is 1.4-4.2%.
 10. The high-modulus glass fiber composition of claim 1 comprising the following components expressed as weight percentage: SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.1-4.3% La₂O₃ less than or equal to 1.5% CeO₂ less than or equal to 1.2% CaO  6-10% MgO 9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.6, the range of the weight percentage ratio C2=SiO₂/CaO is 5.8-9.3, and the range of the weight percentage ratio C3=MgO/(CaO+SrO) is 0.9-1.6.
 11. The high-modulus glass fiber composition of claim 1 comprising the following components expressed as weight percentage: SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.1-4.3% La₂O₃ 0.05-1.2%  CeO₂ 0.05-1%   La₂O₃ + CeO₂ 0.1-2%   CaO  6-10% MgO 9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1.5%

wherein, the range of the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is greater than 0.7, the range of the weight percentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weight percentage ratio C3=MgO/(CaO+SrO) is 1-1.5.
 12. The high-modulus glass fiber composition of claim 1 comprising the following components expressed as weight percentage: SiO₂ 55.7-58.9% Al₂O₃   15-19.9% Y₂O₃ 0.5-3.9% La₂O₃ 0.05-1.2%  CeO₂ 0.05-1%   La₂O₃ + CeO₂ 0.1-2%   CaO  6-10% MgO 9.05-9.95% SrO less than or equal to 2% Li₂O + Na₂O + K₂O less than or equal to 0.99% Li₂O less than or equal to 0.65% Fe₂O₃ less than 1% TiO₂ 0.1-1%  

wherein, the range of the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.75-0.97, the range of the weight percentage ratio C2=SiO₂/CaO is 6.3-8.5, and the range of the weight percentage ratio C3=MgO/(CaO+SrO) is 1-1.5.
 13. The high-modulus glass fiber composition of claim 1, wherein the range of the weight percentage ratio C1=Y₂O₃/(Y₂O₃+La₂O₃+CeO₂) is 0.75-0.97.
 14. The high-modulus glass fiber composition of claim 1, wherein the range of the weight percentage ratio C4=La₂O₃/CeO₂ is greater than
 1. 15. A glass fiber being produced from the glass fiber composition described in claim
 1. 16. A composite material incorporating the glass fiber described in claim
 15. 